High severity7.5NVD Advisory· Published Oct 2, 2026

CVE-2026-104430

Description

Zebra zebrad 4.5.0 and zebra-script 7.0.0 count P2SH redeem script signature operations in legacy mode rather than zcashd's accurate P2SH mode, overcounting CHECKMULTISIG preceded by OP_1 through OP_16 as 20 sigops and causing a consensus divergence. Remote attackers can broadcast P2SH spends using low-threshold multisig redeem scripts so that a block zcashd accepts exceeds Zebra's inflated MAX_BLOCK_SIGOPS count, causing Zebra nodes to reject it and stall off the chain.

Affected products

Zebra/zebradllm-fuzzy
Zebra/zebra-scriptllm-fuzzy
ZcashFoundation/Zebrallm-fuzzy

Patches

Vulnerability mechanics

References

github.com/ZcashFoundation/zebra/security/advisories/GHSA-2prc-cj5x-4443nvd
www.vulncheck.com/advisories/zebra-4.5.0-consensus-split-via-p2sh-sigop-overcountnvd

News mentions

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cvss	0.488
epss	0.000
exploit	0.000
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ransomware	0.000